Air actuated disc brake for heavy vehicles such as trucks and buses are typically provided with a mechanism to manually rewind the adjuster mechanism that maintains the correct pad to rotor clearance as friction material wears. The mechanism is required so that unworn pads can be fitted into the space previously occupied by thinner worn pads. The mechanism may also be required to advance pads towards the rotor in certain circumstances, typically to take up excess clearance when new, unworn pads are fitted.
Disc brakes of this type are fitted to a wide variety of vehicles, often with different available space envelopes into which the caliper, and in particular the air actuator that is mounted to the caliper, can be fitted. As a result, the air actuator may be mounted at a variety of angles with respect to the caliper.
When the air actuator is mounted at certain angles, this may restrict access to the part of the manual adjuster apparatus where a technician will be required to attach a spanner, wrench or the like to rewind adjuster mechanism. This can be inconvenient to the technician, and/or may require a proprietary tool to be used for access.
This issue may be particularly acute for disc brakes in which the manual adjuster apparatus is centrally mounted, as may be the case for single piston brakes where a shaft of the manual adjuster system is co-axial with the piston and extends inboard through the housing of the brake caliper to be accessible on the inboard face of the housing at a location where access may be prevented by a lowermost part of the air actuator. An example of and air disc brake of this configuration is EP0730107 (Perrot Bremsen).
The present invention seeks to overcome, or at least mitigate, the problems of the prior art.